The Ganged Phased Array Radar - Risk Mitigation System (GPAR-RMS) was a mobile ground-based sense-and-avoid software and hardware system for Unmanned Aircraft System (UAS) operations developed by the University of North Dakota. The Risk Mitigation (RM) software subsystem for GPAR-RMS was designed to estimate the current risk of mid-air collision, between the Unmanned Aircraft (UA) and a General Aviation (GA) aircraft flying under Visual Flight Rules (VFR) in the surrounding airspace. The results of data mining an aircraft telemetry data set from a consecutive nine month period in 2011 are...